The present invention relates to a deratization apparatus with remote terminals, more specifically to a deratization central unit controlling several remote terminals provided with vibration generating means.
Several deratization devices are currently in use among one can list devices provided with sound generating means. Such an installation as disclosed by the European Patent EP-A1-0 042 644 provides for an electronic central control unit, said unit modulating a control signal which is being wired to several remote terminals, said remote terminals including means to generate a signal of a frequency according to the incoming control signal.
As the experiments in the field of deratization had shown that rats are sensitive to low frequency signals, said means are generating a signal in the range of 50 Hz. However further experiments had shown that better results are achieved by varying the frequency and the amplitude of the generated signals. Therefore the central control unit is generating, according to a preset logic, signal series having variable frequencies and amplitudes. Said signal series are conveyed to the remote terminal through electrical wires and actuate a ferromagnetic mass to vibrate, the latter being mechanically connected to the building to be deratized. Thus a "micro-seism" stressing the rats is generated, the low frequency vibrations driving thus rats away.
Although the deratization device mentioned hereinabove has proved to be very effective in driving off the rats, the provision of wiring in large buildings from the central unit to the remote terminals is technically difficult, time-extensive and costly. In fact, as the deratization problem occurs mostly in old buildings, where there is just an electrical power supply net and no other wiring, separate conductors are needed to connect the central unit to said remote terminals, said separate conductors carrying the control signal modulated by said central unit.
Further, the deratization device described hereinabove has also proved to be not flexible enough, as there is no way of controlling independently the working status of each remote terminal.